Typewriting machine



Jan. 12 1926. .1,569,076

W. A. DOBSON TYPEWRITING MACHINE Filed Dec. 12. 1922 Patented Jan. 12, 1926.

UNITED STATES PATENT osi-vich:.N

WILLIAM A. DOBSON, OF BRIDGEPORT, CONNECTICUT, ASSIGNO'R TO NDERWOD TYPEWRITER COMPANY, 0F NEW YORK, N. Y., A CGRPQRATION OF DELAWARE.

'IYPEWRITINGV MACHINE.

Application filed December 12", 192%. Serial No.V 606,361?.

To all colto/m. #may concern:

Beit known that I, VILLIADI A. DonsoN, a citizen of the United States, residing in Bridgeport, inthe county of Fairfield and State of Connecticut, have invented certain new and useful Improvements in Typewriting Machines, of which the following is a specilication.

The present invention relates to a si-lent key-mechanism for typewriting machines; that .is to say, to a mechanism by means of which a key may function to print a character and concomitantly to actuatey a ribbonvibrator,` or to act on other mechanisms in typewriting machines, wh-ile nevertheless being` silent in the respect that it is ineffective to cause letter-space movement of the platen relative to the printing point.

Often, particularly in certain languages, a letter or character should have a particular accent-mark printed directly above it, or should bev underscored; and, if keys bearing such accent or other special characters areI` 'net disconnected from the letter-space mechanism, the carriage must be back-set after one key is opera-ted, to permit both the letter and the accent key, for instance, to print at the same point in the line.

Silent-key-mechanism which obvia-tes the necessity of such back-setting is not broadly new with the present invention. In the prior art, however, the-silent-key-mechanism generally involves actuation of the universal bar or its equivalent, and consequently involvesv the presence andi operation of1 some specialv device, suchA that theuniversal bar, althouglr actuated, is nevertheless disabllec to elfeet letter-space movement.

EvenV where the silent-key-lever has been disconnected from the universal bar, to be' operable independentlythereof, its connections to the ribbon-vibrator, to provide for a variable throw of the ribbon-vibrator for printing by the silent-key in any selected color Zone of a biclirome ribbon, have notv been entirely satisfactory.

An. object of the invention is the provision of means,l simple in construction and reliable in action, for` actuating the ribbonvibrator from the silent-key-lever, independently ofl the universall bar, such that the silent-key-characters may be printed through any selected color Zone of aV bi'- chrome ribbon with the same facility as are the characters of thekeys.

It may happen: that a single silent-key will not provide for! all the desired charac-` ters in: the nature of accent-characters; and, to meet this contingency, an object of the invention is the yprovision of additional silent-keys, and of means whe'rr-iby',` without operationl of the universal bar, the ribbon- Vibrator inlay be actuated' from any selected one of apluraility of silent-keys, anda variable throw' of the vibratoieffected by the selected. silent-key, for writing in any selected color zone of a bichroine ribbon.

Other features and advantages will hereinafter appear.

the accompanying" drawings,

Figure 1 a perspective View of so much of an TJnderwood standard portable typewriter as involves the present invention.

Figure 2 is a top plan view` of the drawbar or' link willich connects the silent-keylever' toA the' intermediate ribbon-vibratorl'ever. Figure i-s a top' plan View of the intermediateI ribbon-vibrator-lever;

Itilgurel tais a top plan viewf, showing the connections of the silent-key, the ribbon color-control lever and the universal bar to the intermediate ribbon-vibrator-lever; the pa-itsbeing norma-'lf positionY and the colorcontrol lever being set for the black ribbonzone. y

Figure 5 is view similar to Figure l?, except that the color-control l'ev'er is set for the redf ribbon-zone.

Figure (3L i's a view similar tol 11 igure 5, except that the parts are in' the vposition assumed when the silent-key is depressed.

Character keys, one of which is shown at 15, when actuated, move key-levers lGl around a common fulcrinn plate 17 supported on a cross-bar 18, extending between' the sides 19F of the main frame. Tliekeylev'er 116, when actuated', moves against the tension, of a spring 22 to swing a bellcrank, not shown, about a fulbrum 24- on a letter and numeral bracket 25 secured to a cross-bar 26, also extending between the sidesy 139v of the main' frame" The bell-crank pull'son a link not shown, tocause thev typesto strike against the front side of a platen 27.

The platen is journaled in a carriage 28, which may be urged, from right to left in the usual manner by a spring drum (not sho-wn). To cause the carriage to move from one letter-'space position to another, while typing, there is provided a universal bar 29 pivotally supported by means of arms 30 on a rock-shaft 31 and with which the keylevers engage, when depressed, by means of shoulders or lugs 32 on the key-levers. The rock-shaft 31 is journaled in brackets 33, one at each end thereof,k secured to the cross-bar 18. An arm (not shown) on the universal bar connects with and operates cscapement mechanism (not sho-wn) for controllingl the letter-feed movements of the carriage; so that, upon each depression of any letter or numeral key-lever, the carriage may have a letter-space advance under the action of. the spring drum. Escapement mechanism suitable for this purpose is shown in United States Letters Patent to Dobson, No. 1,417,304, dated May 23, 1922.

At each type-stroke, a ribbon 34 is moved into the path of the striking type-bars. This movement of the ribbon is effected by an iipwardly-extending crank 35 fast on the rock-shaft 31 of the universal bar. `The crank 35, at the upper end thereof, carries a pin 36 to which is rotatably connected a strap 37 carrying an ear 38; the strap being held on the pin by the head 39 of the latter. Pivotally connected at 40 to the ear 38 is an arm 41, the forward end of which has a oneway connection at 42 with the intermediate or ribbon-vibra-tor-lever 43; that is to say, the arm 41 actuates the ribbon-vibratorlever only in the forward movement of the crank 35. For reasons more fully to be hereinafter described, the one-way connection referred to permits the ribbon-vibratorlever to be free to move forward without involving movement of the crank 35 or rockshaft 31. The one-way connection of the arm 41 to the lever 43 is shown and described in the Dobson patent referred to. Briefly, the arm 41 has an enlarged part 44 terminating in shoulders 45,- beyond which the armv is of reduced cross-section, as shown at 46. The reduced portion 46 is adapted tomove freely in a threaded sleeve 47 on the intermediate lever. Onforward movement of the crank arm 35 and the arm 41, the shoulders 45 of the arm 41, by engagement with the rear end of the sleeve 47, cause the intermediate lever to be rocked forward. Then the intermediate lever is rocked forward other than by means of the arm 41,

y however, the sleeve 47 slides over the reduced portion 46 of the arm 41 without drawingon the latter to rock the crank arm The connection between the arm 41 and the intermediate lever 43 is a shiftable connection, hereinafter more fully to be dcscribed` for varying the throw of the intermediate lever in setting the ribbon-vibrator fort-'he different ycolor Zones of the ribbon.

Topermit of such shift, the sleeve 47 on the arm 41 carries on its underface a pin 41a which projects into an arcuate slot 4b in the intermediate lever. A washer 49, see Figure 1, secured to this pin below theintermediate lever prevents upward displacement of the pin in the slot 48. The slot 48is curved on a radius struck from the pivot 50 of the pivotal connection of the arm 41 to the ear 38 on the crank arm 35, so that the arm 41 may be swung from one to the other end of the slot 48 in the intermediate lever.

The intermediate lever is pivotally mounted on a stud 51 threaded into and secured to a bridge 52, which connects the cross-pieces 18 and 26. In order that the intermediate lever may not have up-anddown angular play, it is of U-shaped formation at the right-hand side; comprising two parallel arms; to wit, an upper arm 54 and a lower arm 55 connected by a vertical piece 56; the arms 54 and 55 being spaced well apart, and the stud 51 passing through both of these arms. T he portion of the lever having the slot 48 is unitary with the upper arm 54; and the vertical part 56 of the lever carries vertical, elongated, rearwardly-directed parallel ears 57 for receivingtherebetween a stud or pin 58 on a lever which forms an element of the ribbon-vibrator mechanism.

The last-named lever is a bell-crank lever pivoted at 59 to a rail or cross-piece 60 forming part of the platen-shift frame. This lever has a depending, substantially vertical arm 61 which carries the pin 58, by means of which the lever is actuated from the intermediate or ribbon-vibrator lever 43. Another arm 62 extends substantially horizontally leftward and terminates in a yoke 63, in which is engaged a pin 64 on the ribbonvibrator 65. It follows from the foregoing that the forward swing of the intermediate lever 43 by the crank arm 35 on the universal bar or rock-shaft 31` results in a clockwise swing of the arm 61 and an upward movement of the arm 62, thereby actuating the ribbon-vibrator. The latter is pro-vided with eyelets 66, through which the ribbon is threaded and is guided by ears 67 on parallel arms 68 of a vibrator-guide suitably secured to the shift-frame rail 60.

The carriage 28 has its movements in letter-feed and return directions on the shiftframe; the rail serving as a runway support for the forward portion of the carriage, and there being` a similar runway support for the rear of the carriage (not shown). By means not shown in the drawings of the present application, but which are fully shown in United States Letters Patent to Dobson, No. 1,335,956, dated April 6, 1920, the case-shift frame, with the carriage thereon, is adapted to be shifted upward on the main frame from lower-case CII Lenaerts position to either a middleoase or an upper-case position; and suitable stopsA for determining these case positions are provided.

Since the ribbon-vibrator and the ribbon?.

f on the main frame and' has no case-shift movement. It is to allow for the case-shift movement of the arm 6l and pin 58 thereon, with respect to the intermediate liever 43, that the elongated ears on the intermediat-e liever are provided. These ears, with the pin 5S, form a. pinandslot connection between the arm 6l and the ribbon-vibrator lever 413; and this connection is maintained whatever the case position of the case-shift frame.,

The ribbon is shown as having two colo-r nenes, to wit, an upper black r/fone 69 and a lower red Zone 70. It follows that a greater thro-w of' the ribbon-vibratoris required for l printing in the red' zone than for printing in the black zone. To obtain the desired variation in throw of the ribbon-vibrator, the setting of the connection of' the crank arm 35 to the intermediate lever 43 is changed by means of a color-control lever 71. This lever, pivoted at 72 to a bracket 73 on the main frame, carries on its forward end a finger-piece 74, and at its rear end is connected by a link to the arm 4l, which connects the crank arm 35 to the intermediate or ribbon-vibrator-lever.

ln Figure 4 the Finger-piece 74 is shown in its extreme right-hand position, with the link 75 and the arm 41 in their extreme left-hand positions, as determined by the let-hand end of the slot 48 of the intermediate lever- In Figure 5 the ingenpiece 74 is shown in. its eXtremeleft-hand posi-v tion with the link 75 and the arm 41 in their extreme right-hand positions, as determined by the right-hand end of the slot 48. Since in Figure 5 the point of connection of the arm 41 to the intermediate lever is nearer the pivot 51 of the latter than it is in Figure 4, actu-ation oi' the universal bar will result in a greater throw of the ribbon-vilnator with the Figure 5A setting than with the Figure 4- setti-ng. The finger-piece 74 may, however, be set at a point intermediate its Figure 4 and Figure 5 positions, in which event the arm 4l will register with the central portion of' the slot 48 in the intermed-ite lever. It will be noted that the slot is enlarged at its cen-ter; This enlarge ment is sulicient to permit of movement of the crank arm 35 with the arm 4l without effecting movement of the intermediate lever. The rcentral posi-tion is the so-called neutral position, in which the universal bar may be operated `without operation` ci" the ribbonfvibrator. For convenience, a color plate T6. .is fixed to the front plate 7 7 of the machine above the linger-piece 74 ot the color-control lever. This color plate shows three color sections, to wit, a black section 78, a white or neutral section 7 9 and a red section 80, and the ribbon will print black, red or not at all, according as the finger-r piece is set over one or the other of these color sections. The ribbon-vibrator-lever is returned to normal position after each actuation Vthereof by means `of a coil spring 8l on the pivot stud 5:1. This spring is conf nected at one end to the bridge 5.2L, on which the stud 51 is secured, and at its other end to the intermediate lever 43,

A silent-keyI 83l is carried by a lever 84 fulcrumed, as in. the case ot the letter and numeral key-levers 1G, on the plate 17,v having a coil spring 22a for returning the same to normal position. Since one or another of the characters 85 on the silent-key 83 is to be written directly over or under a previously written.` letter, letter-feed movement of the carriage is not desired when the silent-key is operated, and so thel silentfkeyliever 84 is not provided with the shoulder or lug 3.2 for operating the universal' bar 29.

No. actuation ot the crank arm` 35 on the uni.- versal bar or rock-shaft therefore takes place upon depression of the silent-key- As in the case of the other keys, however, it is necessary to operate the ribbon-vibrator by the silent-key; and for this purpose the following means are provided.

The silent-key-lever 84 has an arm 86'- projecting upward therefrom. This arm is adapted to engage a roller 87 jou'rnaled in an ear 88 oi a bracket 89- on a slide or link 90, and to cause the slide 90J to be pushed forward when the silent-keyisdepressed. The slide 90, at its forward end, is supported on a bracket 91 on the front plate 92 of' the machine; and the forward end of the slide is set within and guided a slot in the bracket 91. At its rear the slide 901 is guided by means of a yoke 93 thereon, which embraces the stu-d or pivot 5l of the intermedi ate lever. rlhe slot 94 iiorm-ed the yoke permits forward and rearward movement of' the sllide relative to the stud 511. At its rear the slide also connects to and' forms part of a plate 95 having a slot 96 therein: similar to the slot 48 in the intermediate lever. The plate 95 lies Hat upon the intermediate lever in such manner that, in the Figures/4 and 5 positions of the parts, that is to say, the posi-tion of the parts assumed when the silent-key is not operated, the slot 961m the plate 95 registers with the slot 4814 in. the intermediate lever. The presenceof the slide and plate therefore inl nowise affects the movement of the link 75' and the arm 4l when the silent-key isznot operated. 'The pin 41a, which is carried by the anni 41 and III . levers,

which passes through the slot 48 in the lever 43, also passes through the slot 96 in plate 95; so that when, as indicated in Figure 6, the slide 90 is drawn forward upon depression of the silent-key, the plate 95, through the pin 41, causes the intermediate lever 43 tobe rocked around its pivot 51, thereby actuatingl the ribbon-vibrator in the manner hereinbefore described. In Figure 6 the pin 41a is shown at the right-hand end of the slots 48 and 96, as determined by the position of the finger-piece 74 of the color-control lever over the red section 80 of the indicator plate, for printing of the silent-key character through the red Zone of the ribbon. .It is obvious, however', that if, when the parts are in the Figure 4 position, for printing on the black ribbon-zone, the silent-key be operated, the slide 90 will rock the intermediate lever; although, as hereinbefore pointed out, the same movement of the slide, in this instance', will elfect a shorter throw of the intermediate lever than when the color-control lever is in the Figure 6 position. f

It maybe desired to have more silent-key characters than can be taken care of by one silent-key. In this event two or more silentkey-levers .maybe employed. In Figure 2 two silent key-levers 84 and 97 are shown. The lever 97 Ris in all respects constructed and operated like the lever 84. A second bracket 98, somewhat similar to the bracket 89 is,.however, secured to the under face ofy the link or slider 90; and )this bracket, like thebracket 89, carries a roller 99 for engagement with the u right arm 86 of the silentkey-lever 97. peration of the lever 97 therefore results in the same movement of the slide90 as is effected by means of the lever 84. The brackets 89 and 98 aresecured to the slide 90 by means of screws 100, which are passed throughslots 101 in the slide and which thread into the brackets. The slots 101 permit of adjustment of the position of the rolls 87 and 99,V so that in assembling the machine the rolls may be properly set with respect to the'uprightarms 86 on the silent key-levers. By means of other rolls similar' to rolls 87 and 99, on the slide 90, additional silent-key-levers may be made tooperate the slide or link.

Variations may be resorted to within the scope of the invention, and portions of the improvements may be used withoutothers.

Having thus described my invention, I claim:

1. In a typewriting machine, a platen, a platen-carriage, mechanism for effecting a letter-feed of the carriage, a universal bar for controlling the letter-feed mechanism, type-operating levers, means for operating the universal bar from the type-operating a ribbon-vibrator, a lever for eliecting a variable throw of the ribbon-vibrator to present to the printing point the selected color-zone of a bichrome ribbon, said lever including an arcuate slot, means for operating the ribbon-vibrator-lever from the universal bar, an accent or silent-key-lever nonoperative upon the universal bar, and means for operating the ribbon-vibrator from the accent or silent-key-lever independently of the universal bar, said last-mentioned means comprising a link overlying the ribbonvibrator-lever, and moving idly therewith during actuation of the type-operating levers, a shoulder on the link, a finger on the silent-key-lever for engagement with the shoulder to actuate the link, said link having a slot in registry with said slot of the variable-throw lever, a pin passing through the slot of each of the overlying parts to connect the same for movement as a unit, and means for shifting the pin along said slots to change the point of connectionof the link to the ribbon-vibrator-lever, to vary the throw of the latter.

2. In a typewriting machine, a platen, a platen-carriage, mechanism for effecting a letter-feed of the carriage, a universal bar for controlling the letter-feed mechanism, a type-operating levers, means for operating thek universal bar from the type-operating levers, a ribbon-vibrator, a lever for effecting a variable throw of the ribbon-.vibrator to present to the printing point the selected color-zone of a bichrome ribbon, means for operating the ribbon-vibrator-lever from the universal bar, and accentor silent-key-lever non-operative upon the universal bar, and means for operating the ribbon-vibrator from the accent or silent-key-lever independently of the universal bar, said last-mentioned means comprising a floating link positively connected to the ribbon-vibratorlever, and moving idly therewith during actuation of the type-operating levers, a shoulder on the link, a inger on the accent or silent-key-lever for wiping engagement with the shoulder, and means for changing the point of positive connection of the link to the ribbon-vibrator-lever to vary the throwo'f the latter. Y

3. In a typewriting machine, a platen, a platen-carriage, mechanism for eecting a letter-feed of the carriage, a universal bar for controlling the letter-feed mechanism, type-operating levers, means for operating the universal bar from the type-operating levers, a ribbon-vibrator, a lever for effecting a variable throw of the ribbon-vibrator to lpresent to the printing point the selected color-zone of a bichrome ribbon, means for operating the ribbon-vibrator-lever from the universal bar, an accent orsilent-key-lever non-operative upon the universal bar, and means for operating the ribbon-vibrator from the accent or silent-key-lever independently of the universal bar, comprising a llink positively connected i to the ribbonv-ibrator-rlever., a Vroller on the linfk, a linger on the accent or silent-key-lever .for wiping engagement with the roller, and means for changing the point of positive connection of the .link tothe ribbonvibrator-lever to vary the throw of the latter.

l.. lin a typewriting machine, :a platen, a platen-carriage, mechanism for leli'ecting a letter-feed foil: the carri-age, a universal bar for controlling the letter-steed mechanism, type-operating levers, -means for operating the universal bar from the type-operating levers.v a ribbon-vibrator, a lever for effecting a variable throw :of the ribhonvibrator to present tothe printing point the selected colonzone yot a bichrome ribbon, means for operating `the ribboirvibrator-lever from the universal liar, an `accent or silent-key-lever non-operative upon fthe universal bar, and means for operating the ribbon-vibrator troni the accent or silent-key-lever independently of the universal bar, comprising a link positively connected to the ribbonif'ibratoihlever, a shoulder on the link, a finger on the accent or silent-key-lever for engagement with the shoulder, meansfor adjusting the position of the shoulder on the link, :and means for changing the point of positive connection of the link to the ribbon vibrator-lever to vary the throw of the latter.

In a typewriting machine, a platen, a platen-carriage, mechanism for effecting a letter-feed of the carriage, a universal bar tor controlling the lettenteed mechanism, typeoperating levers, means for operating the universal bar from .the type-operating levers, a ribbon-vibrator, .a lever for effect# ing a variable throw of the ribbon-vibrator to present to the printing point the selected color-zone of a bichrome ribbon, means for operating the ribbonvibrator-lever from the universal bar, an 'accent or silent-keylever non-operative upon the 'universal bar, and means for operating the ribbon-vibrator from the accent or silent-keylever independently of the universal bar, said lastmentioned means comprising a floating link positively connected to the Vribbon-vibratorlever, and moving idly therewith during aetuation of the type-operating levers, means on the accent or silent-key-lever for actuating said floating link, and means for changing the point of positive connection of said link to the ribbon-vibrator-lever, with respect to the pivot of said ribbon-vibratorlever, to vary the throw ot the latter.

(3. In a typewriting machine,`a platen, a platen-carriage, mechanism for effecting a letter-feed o the carriage, a universal bar for controlling the letter-feed mechanism, type-operating levers, means for operating the universal bar from the type-operating levers, a ribbon-vibrator, a lever for effect? ing a vari able throw of the ribbon-vibrator to ipresent to the printing point the selected color-zone of fa bichrome ribbon, means .for operating the ribbon-vibrator-lever 'from the universal bar., an accent or silentekeyslever non-operative upon the universal bar, and means for operating the ribbon-vibrator from the accent or sileifit-key-l'ever independently oi' the universal bar., said lastmentioned means comprising :a floating link positively connected `to the ribbon-vibratorlever, and moving idly therewith `during actuation 'of the type-operating levers, means on the accent or silent--key-lever for actuating the link, and means for chfangingthe point of positive connection of the link to the ribbon-vibrator-lever, `with respect to. the pivot of 'said ribbon-vibrator-lever, to vary the throw of the latter; the link and ribbon-vibrator-lever having a pin-'and-slot connection, one to the other, to permit olf s-iich change in the point of connection.l

T. ln a typewritiirg machine, a platen, a platen-carriage, mechanism for `effecting a letter-feed ot the carriage, a universal bar for controlling the letter-feed mechanism, type-opi-xrating levers, means .for operating the universal bar from the type-operating levers, a ribbon-vibrator, a lever for elfecting a variable 'throw of the ribbon-vibrator to 'present to the printing point the selected color-zone of the bichrome ribbon, means for operating 'the ribbon-vibrator-lever from the universal bar, an accent or silent-keylever non-operative upon said universal bar, and means for operating the ribbon-vibrator from the accent or silent-key-lever vindependently 'of theiiiniversal bar, comprising a link positively "connected to, and in part overlying, vthe ribbon-vibratorflever, said overlying i parts being slotted outwardly with respect to the pivot of the ribbon-vibra toilever; a pin passing through the slots of 'both ot said overlying parts to lock 'the sam-e for movement together, means on the accent or silentkey-lever for actuatingthe link, andmeans for lshifting the pin along said slots to change the point of connection of the link to the rilobon-vibrator-lever, for varying the throw ot' the latter.

8. In a tvpewriting machine, aplaten, a platen-carriage, mechanism for efecting a letter-feed of the carriage, afuniversal bar for controlling the letterhead mechanism, type-operating levers, `means for operating the universal bar from the type-operating levers, a ribbon-vibrator, a lever tor elfecting a variable throw of the ribbon-vibrator 'to present to the printing point the selected 'color-Zone 'of a bichrome ribbon, means for operating the ribbon-vibrator-lever from the universal bar, an accent or silent-keylever non-o`peratii`fe upon said universal bar, and means for operating `the ribbon-vibrator from" the accent or silent-key-lever indellO pendently of the universal bar, comprising a link positively connected to, and in part overlying, the ribbon-vibrator-lever, said overlying parts being slotted outwardly with respect to the pivot of the ribbon-vibratorlever; a pin passing through the slots of both of said overlying parts to lock the same for movement together, means on the accent or silent-key-lever for actuating the link, an arm carrying said. pin, and a lever connected to the pin-carrying arm to move the same to shift the pin along` said slots to change the point of connection of the link to the ribbon-vibrator-lever, for varying the throw of the latter. l

9. In a typewriting machine, a platen, Aa platen-carriage, mechanism for effecting a letter-feed of the carriage, a universal bar for -controlling theletter-feed mechanism, type-operating levers, means for operating the universal bar from the type-operating levers, a ribbon-vibrator, a lever. for effecting la variable throw of the ribbon-vibrator to present to the printing point theselected color-Zone of a bichrome ribbon, means for operating the ribbon-vibrator-lever from the universal bar, an accent or silent-key-lever non-operative upon said universal bar, and means for operating the ribbon-vibrator from the accent or silent-key-lever independently of the universal bar, comprising a link positively connected to, and in part overlying, the ribbon-vibrator-lever, said overlying parts being slotted' outwardly with respect to the pivot of the ribbon-vibratorlever; a pin passing through the slotsof both ot' said overlying parts to lock the same for movement together, means on the accent or silent-key-lever for actuating the link, an arm carrying said pin, and a lever connected to the pin-carrying arm to move the same to shift the pin along said slots to change the point of connection of the link to the ribbon-vibrator-lever, for varying the throw of the latter; said pin-carrying arm being connected to the universal bar and having a one-way slip-connection with said pin, whereby the arm and pin thereon may move with the universal bar to actuate the ribbonvibrator-lever, while nevertheless permitting the pin to bemoved by the link from the accent or silent-key-lever without actuation of the universal bar.

10. In a typewriting machine, a platen, a platen-carriage, mechanism for effecting a letter-feed of the carriage, a universal bar for controlling the letter-feed mechanism, type-operating levers, means for operating the universal bar from the type-operating levers, a ribbon-vibrator, a lever for effecting a variable throw of the ribbon-vibrator, to present to the printing point the selected color-Zone of a bichrome ribbon, means for operating the ribbon-vibratorlever from the universal. billy-@I1 aCCGIlG 01 silent-key-lever ,non-operative upon said universal bar, and means for operating the ribbon-vibrator from 4the accent or silentkey-lever independently of the universal bar, comprising a link positively connected to, and in part overlying, the ribbon-vibrator-lever, said overlying parts being slotted outwardly with respect to the pivot of the ribbon-vibrator-lever; a pin passing through the slot of both of said overlying parts to lock the same for movement together, means on the accent or silent-key-lever for actuating the link, and means for shifting the pin along said slots to change the oint of connection of the link to the rib on-vibratorlever, :for varying the thrown of the latter; said slots being enlarged at a part thereof to which the pin may be thrown for movement of the pin by the link from the accent or silent-kev-lever without movement of the ribbon-vibrator-lever.

1l. In a typewriting machine, a platen, a platen-carriage, mechanism for effecting a letter-feed of the carriage, a universal bar for controlling the letter-feed mechanism, type-operating levers, means for operating the universal bar from the type-operating levers, a ribbon-vibrator, a lever for effecting a variable throw of the ribbon-vibrator to present to the printing point the selected color-Zone of a bichrome ribbon, means for operating the ribbon-vibrator-lever from the universal bar, a plurality of accent or silentkey-levers non-operative upon said universal bar, and means for operating the ribbonvibrator from either of the accent or silentkey-levers independently of the universal bar, comprising a link positively connected to the ribbonvibrator-lever, rollers on the link, a finger on each of the accent or silentkey-levers for wiping engagement with one of the rollers, and means or changing the point of positive connection of the link to the ribbon-vibrator-lever to vary the throw ot' the latter.

l2. In a typewriting machine, a platen, a platen-carriage, mechanism for effecting a letter-feed of the carriage, a universal bar for controlling the letter-feed mechanism, type-operating levers, means for operating the universal bar from the type-operating levers, a ribbon-vibrator, a lever for eifecting a vvariable throw of the ribbon-vibrator to present to the printing point the selected color-Zone of a bichrome ribbon, means for operating the ribbon-vibrating-lever from the universal bar, a plurality of accentor silent-key-levers non-operative upon the unversal bar, and means for operating the ribbon-vibrator from either of the accent or silent-key-levers independently of the universal bar, comprising a link positively connected to the ribbon-vibrator-lever, rollers on the link, a finger on each of the Yaccent or silent-key-levers for wiping engagement with one of the rollers, means for adj usting; the position of the rollers, independently oi' each other, on the link, and means for changing the point ot positive connection of the link to the ribbon-vibrator-lever to vary the throw of the latter.

13. In a typewriting;` machine having` a letter-feeding carriage, type-operating keys, a universal bar operated by said keys and controlling the carriage, ribbon-vibrating mechanism operable by said universal bar, bichrome mechanism settable for diiierent throws of the ribbon-vibrator, a silent key non-operative upon the universal bar, and means for enabling said silent key to operate said ribbon-vibrator at the different p0- sitions to which said bichrome mechanism is set, said vibrating mechanism including a lever operable by said universal bar, a link connected to move idly with said lever during the operation ol? said type-operatingl keys, and means to enable the silent key to actuate said link and thereby operate said lever to vibrate the ribbon.

l'a. In a typewriting,` machine having` a letter-feeding carriage, type-operating` keys, a universal bar operated by said keys and controlling the carriage, ribbonvibrating` mechanism operable by said universal bar,

bichrome mechanism settable for dierent throws of the ribbon-vibrator, a silent key non-operative upon the universal bar, and means for enabling said silent key to operate said ribbon-vibrator at the different positions to Which said bichrome mechanism is set, said vibrating mechanism including a lever operable by said universal bar, a link connected to move idly with said lever during the operation of said type-operating keys, and means to enable the silent key to actuate said link and thereby operate said lever to vibrate the ribbon at all positions to which the bichrome mechanism is set.

15. In atypevvriting machine having a letter-feeding,` carriage, type-operating keys, a universal bar operated by said keys and controlling the carriage, ribbon-vibrating mechanism includinga lever operable by said universal bar, a link connected to move idly with said level' during the operation of said typebperating keys, said link having, a plurality of indivdually-adjustable shoulders, and a plurality of silent keys, each including` a finger arranged to press against one of said adjustable shoulders to actuate the link and thereby operate said lever to vibrate the ribbon.

VILLIAM A. DOBSON. 

